These settings apply to all FedEx Freight accounts and can be accessed from Setup > Carrier Interfaces > FedEx Freight > Settings.
Reference Fields
Reference fields allow you to define additional information for the shipment; for example, you can define a field that you want to print on the FedEx Freight BOL. Aptean Ship supports up to 3 different reference fields at the shipment level.
Specify the shipment fields to include as reference fields by selecting them from the drop-down lists. You can type into the magnifying glass field to search for and select another shipment field.